I know where you are coming from in that I have and still ue Thunderfury. First bit of advice I would give is to not pay attention to anyone unless you're sure they know what they are talking about. I was standing in IF just yesterday and some clown walked by and felt the need to "/s lawl still usinf Thunderfury at lvl 70 >bleeping< noob"
Ok, so don't pay attention to lvl 68 hunters walking around the city imparting thier boundless wisdom on the masses.
The fact that it is a debate as to whether or not it is good enough is justification enough to for me to leave King's Defender as my back up weapon. Which is better? The better question is: Does it matter that much?
I still use it 100% of the time in raiding. Granted, we just have Gruul down and are working on Magtheridon but we have some outstanding DPS that cannot touch my threat. (we have some weak DPS that couldn't get a sniff if I wielded a mining pick) I have superior gear to my place in progression and perhaps if the rest of the raid suddenly caught up we'd be ahead of where we are and that's something I would have to revisit.
Its a great weapon that can do so many things. I wouldn't gove mine up until BT/Hyjal for the axe and sword that drop in each respectively. The Mallet would really make me think twice, I suppose, but I would let it go to my OT first and then, we aren't yet in SSC.
your hat may be nice, but I have the little white tank top that says Legendary right across my boobs. I win. (or more correctly, H wins)